They're both general-purpose high level languages suitable for application programming. The difference isn't so much in the sort of software you can write, but rather what you want your development/testing/debugging experience to be like.

I've never used Python, but I like Haskell for the kinds of problems where I'm trying to do something complicated and a little confusing, and I want the compiler to let me know if I've asked it to do something that doesn't make sense. That sort of thing can save a lot of time in the long run, and I usually feel good that the resulting software is reasonably robust. I expect a good Python programmer could write an equivalent program, it's just not the way I like to work.

Libraries are of course often a deciding factor, and so are performance requirements.